The beginnings of a new parameter system.

apps/systemlib/param/param.c

@@ -0,0 +1,110 @@
+/**
+ * @file param.c
+ *
+ * Global parameter store.
+ */
+
+#include <string.h>
+#include <stdbool.h>
+
+#include <unistd.h>
+
+#include "param.h"
+
+/**
+ * Array of static parameter info.
+ */
+extern char __param_start, __param_end;
+static const struct param_info_s	*param_info_base = (struct param_info_s *)&__param_start;
+static const struct param_info_s	*param_info_limit = (struct param_info_s *)&__param_end;
+#define	param_info_count		((unsigned)(param_info_limit - param_info_base))
+
+static bool
+handle_in_range(param_t handle) 
+{
+	return (handle < param_info_count);
+}
+
+param_t
+param_find(const char *name)
+{
+	param_t param;
+
+	for (param = 0; handle_in_range(param); param++) {
+		if (!strcmp(param_info_base[param].name, name))
+			return param;
+	}
+
+	/* not found */
+	return PARAM_INVALID;
+}
+
+enum
+param_type_e param_type(param_t param)
+{
+	if (handle_in_range(param))
+		return param_info_base[param].type;
+
+	return PARAM_TYPE_UNKNOWN;
+}
+
+size_t
+param_size(param_t param)
+{
+
+	if (handle_in_range(param)) {
+		switch (param_info_base[param].type) {
+		case PARAM_TYPE_INT32:
+		case PARAM_TYPE_FLOAT:
+			return 4;
+
+		case PARAM_TYPE_STRUCT ... PARAM_TYPE_STRUCT_MAX:
+			return param_info_base[param].type - PARAM_TYPE_STRUCT;
+
+		default:
+			return 0;
+		}
+	}
+
+	return 0;
+}
+
+int
+param_get(param_t param, void *val)
+{
+	if (handle_in_range(param)) {
+
+		/* XXX look for updated value stored elsewhere */
+
+		switch (param_info_base[param].type) {
+		case PARAM_TYPE_INT32:
+			*(int32_t *)val = param_info_base[param].i;
+			return 0;
+
+		case PARAM_TYPE_FLOAT:
+			*(float *)val = param_info_base[param].f;
+			return 0;
+
+		case PARAM_TYPE_STRUCT ... PARAM_TYPE_STRUCT_MAX:
+			memcpy(val, param_info_base[param].p, param_size(param));
+			return 0;
+
+		default:
+			return -1;
+		}
+	}
+	return -1;
+}
+
+int
+param_set(param_t param, void *val)
+{
+	if (handle_in_range(param)) {
+
+		/* XXX maintain list of changed values */
+
+	}
+	return -1;
+
+}
+